Presence enabled managed services are known in the art. Presence enabled managed services enable presence information of a presentity to be provided to a presence requester. The presence information denotes the presentity's ability and availability to communicate with the presence requestor. Presence information is represented as an extensible markup language document (XML) called a presence document that is a record of the presence associated with the presentity at a given point in time. This presence document is stored in a presence server, such as an IP Multimedia Subsystem (IMS) compliant Session Initiation Protocol (SIP) application server. IMS is an architectural framework for delivering internet protocol (IP) multimedia to mobile users. The (SIP) is a signalling protocol, widely used for setting up and tearing down multimedia communication sessions such as voice and video calls over the Internet.
However, there remains a number of deployment complexities with respect to the actual deployment of a presence server in a telecommunications network. First, most telecommunications carriers have very few IMS subscribers with IMS compliant handsets.
Second, presence information in a typical network will require the collection of presence information from an IMS core and a number of other legacy non-IMS network components. These non-IMS network components include location platforms, the Home Location Register (HLR) infrastructure, the legacy data network, which includes over the air interfaces such as GPRS, 1XRtt, EVDO, Wifi networks and others, and other legacy instant messaging platforms that are not SIP compliant, such as an external IM gateway.
Third, the obtaining of presence information is complicated by several factors. In the absence of a custom interface written for these legacy sources, a pull based model may be required to collect presence information from these sources. A pull based model may be very expensive in terms of network resource consumed and sometimes is of very high latency. For example, a location request (which could be one of the nodes of the presence document) could take over 10-12 seconds in most wireless networks, making it very difficult to incorporate this element of presence efficiently.
To leverage presence services to build higher level composite services, a set of immediate aggregators and independent software vendors (ISV's) outside the carrier domain will probably be a big consumer of basic presence services from the telecommunications service provider. As such, a more logical implementation interface for these external requests are paradigms such as web services rather than SIP based signaling. This is because exposing SIP outside the services provider domain has a number of issues associated with it.
Notifications to presence requesters who have subscribed to presence information may follow established web services based mechanisms such as Parlay X 2.0 and Parlay X 2.1 or protocols such as REST (Representational State Transfer).